


I am your density

by literaryoblivion



Category: Teen Wolf (TV)
Genre: Anal Sex, Bottom Derek, Double Penetration, Future Fic, M/M, Plot What Plot/Porn Without Plot, Self-cest, Sexual Content, Threesome, Threesome - M/M/M, Time Travel
Language: English
Status: Completed
Published: 2013-11-09
Updated: 2013-11-09
Packaged: 2017-12-31 22:49:00
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,989
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1037297
Author URL: https://archiveofourown.org/users/literaryoblivion/pseuds/literaryoblivion
Summary: <blockquote class="userstuff">
              <p>One minute Stiles is minding his own business, staring at his computer (and maybe he’s researching and maybe it’s porn; he’s alone and he deletes his internet history, okay?), and the next minute he is staring wide-eyed at an older version of himself (he did one of those aging things to his picture out of boredom once). </p><p>Then Derek shows up too.</p>
            </blockquote>





	I am your density

**Author's Note:**

  * For [grimm](https://archiveofourown.org/users/grimm/gifts).



> This is a slightly belated birthday fic for [Grimm](http://itslookinggrimm.tumblr.com) in which I just tried to combine a bunch of her favorite things. I HOPE YOU LIKE IT.

One minute Stiles is minding his own business, staring at his computer (and maybe he’s researching and maybe it’s porn; he’s alone and he deletes his internet history, okay?), and the next minute he is staring wide-eyed at an older version of himself (he did one of those aging things to his picture out of boredom once). 

“Umm…” he intelligently says to his doppleganger.

“Uhhh…” the older Stiles replies, and really this does not bode well for what the next years will entail for him. “Ahh… shit. I am _not_ supposed to be here.”

“Well, obviously, since I am here…. So, wait. You’re not here to warn me of some wrong choice? Tell me I’m supposed to go left instead of right? If you’re here to stop my progeny from starting a war, you went back too far." 

The older Stiles grins. “Uh, no. None of that. I…. well I probably shouldn’t say, actually. In fact I’m most likely breaking some time rule by even talking to myself. But that’s like only in movies, right?”

“Last time I checked, so was time travel…”

The older Stiles scratches his head and chuckles, “You got a point.”

Stiles gets up, looks out his window and turns back. “I don’t see any paradox monsters or time-vortexes, so we’re probably okay.” The older Stiles agrees with this logic (and why wouldn’t he?) and sits on the bed. Stiles feels like he should be freaking out more about this, but with all the weird shit that happens in Beacon Hills, he has learned to go with the flow. 

“So, McStiles, how long you gonna be here? Am I going to have to pretend you’re some distant relative?”

“McStiles?”

“Yeah, you know… McFly. McStiles. Shut up, it’s your name.”

McStiles shakes his head and continues, “I really think I’ll only be here a few hours tops. My goal wasn’t to time travel, but Deaton said it could be a side effect. I’m sure it’ll wear off in a bit,” under his breath he mutters, “Derek’s probably freaking out.”

Stiles quirks an eyebrow at that, but doesn’t ask. “Okay. So… what should we do until then?”

The older Stiles looks around the room, as if he doesn’t know exactly what his younger self is thinking. “Video games?” McStiles suggests.

Stiles rolls his eyes. “You know me better than that."

“But what if something messes up time with me telling you? What if we create a whole other parallel timeline?!”

“I think that’s your problem.” 

“I’m you!”

Stiles waves him off and plops himself on the bed next to McStiles. “Okay, so what do I end up studying? Do I have a really cool job? You said Deaton, so like am I still here dealing with werewolf stuff? Oh my god, am I magical? What about Scott? What’s he doing? How old are you by the way? And Dad? Is Dad okay? And I heard you mention something about Derek. Why?”

“Holy crap! Why didn’t anyone tell me I was like this? Geez. Okay start over. One question at a time.”

An hour in and his older self had answered all his initial questions and then some. He told him about some funny things that would happen in college with Scott, and Stiles complained about his current state of life only to have his older self reassure him things would work out.

And then Stiles brings up the topic he’s wanted to ask for twenty minutes now but was afraid of the answer.

The older Stiles sighs. “Just ask me, Stiles. I know you want to.”

“This is so weird. Okay, fine. So… uh what about the ladies? Men? Do I have some game or at least go on a date? Something? Because prospects aren’t looking so hot right now. Just please tell me I have some kind of hope in the future?” Stiles looks pleadingly at his older self.

“We did some experimenting in college, of course, which was fun. But I can tell you that right now I’m into guys. _A_ guy….” McStiles smiles fondly to himself, and Stiles smiles, too. He’s glad he’ll get to look like that someday when he thinks of this guy. He decides not to ask for specifics because he knows the older him wouldn’t tell him. Some things have to remain a mystery after all. 

“So are we really good kissers? Come on, you gotta give me something.”

“Actually, if I remember that took some practice. I would say I’m good now, but I don’t think those first few people thought that.”

Stiles’s face falls. “Oh. Could I uh get some pointers?”

His older self scrunches up his nose, “Uh… it’s easier to show than describe.” 

“Okay…” Stiles says because he really doesn’t want to have to wait years to be a good kisser.

The older Stiles clears his throat. “Seriously?”

Stiles shrugs, “I’m you. You’re me. It’s like masturbation, isn’t it? Self-loving?”

McStiles shakes his head, but says, “Uh, okay.”

Stiles scoots a little closer to McStiles and leans in. In the back of his mind he thinks he should be weirded out by this or by the fact he wants to make out with himself, but after the crap he’s had to deal with over these last couple of years, this is not that odd.

“Tilt your head a little to the left,” the older Stiles says, his hands on either side of Stiles’s face to guide him and bring him closer until their lips touch.

Stiles doesn’t really know what to do now that they are actually kissing, if touching lips and not moving can be called that, and part of him is waiting to feel an odd sense of familiarty, like how when Lorrain unknowingly kisses her son in _Back to the Future_ and she says it’s like kissing her brother. The feeling never comes, and nothing else foreboding like a crack of lightning happens, so he takes that as a good sign.

His older self must have been waiting for the same thing because neither of them have moved. Stiles tries first, pulling back a little to kiss McStiles again, a little more forcefully. He opens his mouth to lick at McStiles’s lips, and that must have been good because he hums in approval and pulls Stiles in closer.

He starts trying a few things, opening his mouth wider, using more tongue, until McStiles pulls back to correct him or give him tips: “Don’t open your mouth so wide.” “Don’t do the same thing for too long.” “Yeah, mix it up with some licks and bites or tugs of lips.” “That’s good.”

They move on to touching and stroking fingers through hair, and it’s when Stiles thinks he is actually getting somewhere good that his grumpy neighborhood werewolf decides to show up and climb into his bedroom window. 

“Stiles?!” Derek nearly chokes when he says it, his eyes darting back and forth between both Stiles as they jump apart in alarm.

“Derek?!” they both shout at the same time, only the older Stiles sounds more fond while Stiles sounds scandalized.

“What are you doing here?” both Derek and Stiles say. Derek rolls his eyes while Stile sighs, McStiles snickers.

“Who are you?” Derek growls, pointing at the older Stiles. 

McStiles stands and grins before answering. “Man, it’s so weird to see you like this.” He walks towards Derek, and as he approaches, Derek takes a defensive stance but his face is one of confusion.

As much as he wants to tear into this intruder and throw him out, he smells of Stiles and pack and… something else. He doesn’t move when the older Stiles slowly lifts his hand, and when he places his palm against his cheek, his thumb rubbing against his stubble, Derek doesn’t feel any inclination to flinch. 

“I missed this stubble. Although,” he presses a finger against the corner of Derek’s frown, “I’m glad this doesn’t come out as much, Sour Wolf.” 

Derek’s eyes widen. “St—Stiles?” 

The older Stiles smile grows wider, and he nods.

Stiles comes to stand next to his twin. “It’s McStiles for now, and I guess that takes care of the introductions,” he says, eyeing his older self and feeling what any lesser man would call jealousy over the familiarity McStiles is showing Derek. Which… is weird because he and Derek aren’t really anything (yet… his brain supplies hopefully), and he’s being jealous of himself, which is kind of messed up.

McStiles lowers his hand from Derek’s face and steps back. “It’s a long complicated story that I don’t really want to explain. But, don’t worry I won’t be here much longer I don’t think. But… Stiles and I were in the middle of something, and,” he smirks, “I can speak for the both of us when I say you are more than welcome to join us. 

Stiles eyes bug out of his head, and his mouth hangs open in shock. Dang his older self is bold, and yeah maybe Stiles was entertaining a fantasy in the back of his mind, but he wasn’t going to say anything!

Derek clears his throat and looks down, a distinct blush forming on his cheeks, and rubs the back of his neck. Wow, Stiles doesn’t think he’s ever seen Derek blush before, and he kind of likes it.

His older self chuckles. “Stiles here may not know that look, but I do…”

Derek snaps his head up and quirks an eyebrow at McStiles, who winks at him. Derek still hasn’t said anything, and Stiles is worried that his time-double just ruined every chance of anything happen between him and Derek ever because he’s all confident and offering threesomes willy-nilly. He doesn’t know what happened to make him that way, but he doesn’t think he wants his future-self to turn out that way no matter how cool he seems.

Stiles is ready to send McStiles to Deaton to speed up his back to the future trip when Derek approaches him, stepping so close to him that he is all Stiles can see, his view of McStiles blocked.

“Stiles?” he whispers, Derek’s face is so close to his that Stiles can feel his breath across his lips. “Is he right? Would you want me?”

“Derek, I always want you. Crap. Did I just say that outloud?”

Derek’s lips curl up and he nods, his nose brushing against Stiles’s as he does. “So, is that a yes? 

In answer, Stiles closes the space between them and kisses him. Maybe the little bit of practice he had before helped, but kissing Derek seems to be the most natural and _right_ thing in the world. He pulls back for a breath, and when he does, he catches a glimpse of McStiles.

“This wasn’t what I imagined for my first time. I thought it’d be more vanilla…”

Derek’s brow furrows, his arms are still wrapped around Stiles, and they tighten. “We don’t have to do anything. I don’t care if he is you, I can make him leave.”

Stiles slaps Derek’s shoulder. “Don’t be rude. That’s not what I meant. I mean… when is this ever going to happen again? I think it’d be fun. Do you… do you not want to?” Stiles voice is soft when he asks Derek.

“I haven’t said no, have I?”

“No…” 

Derek leans in, his lips against Stiles’s ear. “I’ve thought about this ever since you came across that cloning spell in Deaton’s book.”

“Oh my god, Derek. Why have you been holding out on me for so long?” 

Derek shrugs. “We’ve been busy.” Stiles nods in agreement.

“So? Shall we get this party started?” McStiles says.

Derek turns to scowl at him, and Stiles laughs. “Looks like you don’t change when you grow up,” Derek mutters. Both Stiles and McStiles wave him off.

“I don’t have much time, so it’s now or never,” McStiles replies while he starts stripping his clothes off.

Stiles gapes at him. “Dude. I don’t know about threesome protocol, but now or never? Really?”

“Oh, like you weren’t thinking it?” 

“You are never using that clone spell, Stiles,” Derek says, staring pointedly at Stiles who has been following suit of McStiles and taking off his clothes. 

“I promise,” he says while he helps Derek speed things along by taking off his signature leather jacket. It is half-way down his shoulders before Derek gets with the program and starts kissing Stiles again as they both help each other out of their clothes. Stiles isn’t really sure where his double went, but at the moment he doesn’t really care because he is _finally_ kissing Derek, and it’s wonderful.

Their kisses turn more heated the less clothes that separate them, and once there is nothing between them, Stiles can feel Derek harden against his thigh, with his own cock just as hard. He’s too overwhelmed by the whole situation to even feel slightly embarrassed about being naked in front of Derek. Or himself… 

“Ah ha!” McStiles says, a bottle of lube in one hand and a couple packets of condoms in the other. Derek and Stiles break apart to stare at him. “Oh, don’t mind me. Just getting supplies. I knew they were somewhere.”

Derek groans and rests his forehead against Stiles’s collarbone. “Maybe he’s from a parallel universe and not the same timeline?” Stiles supplies helpfully, running his fingers through Derek’s hair.

McStiles frowns. “Hey.”

Stiles shrugs a shoulder innocently, and  McStiles mirrors the movement because it could be a possibility, and it would be stupid to hold a grudge against himself. Besides they are all naked, and there are more pressing matters at hand. 

McStiles steps closer to the other two, and even though he hasn’t been fully present for the make-out/striptease session, it’s obvious he’s ready for whatever the next hour will entail. “Uh, so I know I said I experimented in college, but…”

Derek, whose expression has grown to one of impatience, yanks the lube and condoms out of McStiles’s hands. Both Stiles’s and McStiles’s eyes grow, and subsequently their mouths fall open when Derek hands them each a condom and keeps the lube in his hand.

“That answers that question,” Stiles mutters.

“I love it when you get all alpha on me,” McStiles says, and Derek looks back at him in confusion.

“I’m… not an alpha. Not anymore.”

McStiles bites his bottom lip, the first time that night, he looks nervous. “It’s just an expression.”

Stiles pulls Derek’s face towards him. “Can we get back to…?”

Derek presses his lips to Stiles’s and guides him backwards till his knees hit the back of the bed. “Lay down,” he says against Stiles’s lips, and he obeys, flopping backwards onto the mattress. He climbs on top of Stiles on all fours and bends down to kiss along Stiles’s jaw and down his neck, stopping to suck a bruise where his neck meets his shoulder.

“How am I not surprised you’d like the whole marking thing?” Stiles remarks, moaning when Derek sucks harder.

“How am I not surprised you’d like it?” Derek says. Stiles pulls on Derek’s hair to bring him back up to kiss him, and Derek whimpers in pleasure when he does. 

They share a few more kisses before Derek leans back on his knees. He looks to McStiles who has been perfectly content to watch the scene before them as he strokes himself. Derek pops the cap on the lube and squeezes some on to his fingers and then gestures for McStiles to hold out his hand to squeeze some out on his.

“You,” Derek says as he looks at McStiles, “get to help me.” 

“Yes, sir,” McStiles says all too happy to oblige. 

“What about me?” Stiles asks, tone a tinge of petulant.

Derek looks back at the Stiles beneath him. “You get to watch.” Derek doesn’t wait for a reply or argument from either of them before he takes two lubed fingers and reaches behind himself. Both older and younger Stiles moan at the action as they watch Derek finger and stretch himself open. Stiles doesn’t exactly have a great view since he’s still beneath Derek, but the expression on Derek’s face as he hits a certain spot is enough for Stiles.

Before Derek can shout out a command, McStiles is already behind Derek waiting to help. Derek leans forward again, and McStiles takes that as his cue to add his own slicked fingers to Derek’s. He moans at the stretch, and god, the sounds Derek is making are so pornographic, that Stiles is surprised that he hasn’t lost it already.

Now that Derek is hovering over him again, Stiles wraps his arms around his neck to pull him down to kiss him. Derek seems to think that’s a good idea and that he needs both his hands to touch Stiles while he does, so he removes his fingers from his hole, only to have McStiles replace them with his own.

They continue like that for a moment. McStiles fingering Derek and stretching him open with four fingers while Derek licks and kisses the Stiles beneath him. All three of them are breathing hard and cursing under their breath, and Stiles is grateful no one else is home to hear.

“Okay,” Derek grits out when he decides he’s ready. 

“Are you sure?” say both Stiles and McStiles say in unison.

“Yes. You first,” Derek says, lifting his chin to the Stiles underneath him. Stiles nods and helps position himself for Derek. He slowly lowers himself on to Stiles’s cock.

“Shit, _Derek_ ,” he says once he’s fully inside. His brain is blank, and the feeling of Derek all around him is all he can focus on. It’s so much better than he could have imagined, and they haven’t even moved yet.

Derek rests his forehead against Stiles. “You okay?”

“Yeah, you?” Derek nods and shifts his hips before moving up and down slightly. “ _Oh god_ … I don’t… think I can… this might not turn into a threesome after all.”

Derek laughs, “Yes, you can.” He sucks on Stiles’s earlobe as he fucks himself on Stiles’s cock, Stiles helping along by moving his hips in time. It’s a slow steady rhythm, and he never lets Stiles pull out much before sliding back in.

After a little while, Derek stops his movement and makes a motion for McStiles to join them. When he starts to push in alongside Stiles, Derek winces. Stiles looks up at Derek in concern, but Derek shakes his head. McStiles finally pushes all the way in, and Stiles is amazed at it all. Amazed at how much tighter it feels now, amazed that Derek can take both of them, and amazed that he gets to be a part of this and he hasn’t come at the start of it.

It appears like Derek is overwhelmed at it too, when he collapses on top of Stiles, cussing every time McStiles pulls out and pushes back in. Stiles wraps Derek in his arms, caressing him, running his fingers up and down his back, and hugging him close while McStiles slides against him. With each thrust, he brings all three of them closer to climax.

McStiles starts to move faster, and as he does, Stiles holds on to Derek tighter, kissing his shoulder, arm, everywhere he can reach. He doesn’t think he can hold out much longer, and from the look on McStiles’s face, it doesn’t seem like he can either. 

“Derek?” Stiles asks softly. Derek looks up, and Stiles can’t help but think how beautiful and vulnerable he looks in that moment. It’s almost like he’s a different person with all of his shields down and his gruff exterior melted away. And although Derek doesn’t say anything, Stiles can tell he is close just by the pleading look in his eyes. Stiles kisses him while he reaches between them to stroke Derek’s cock. It only takes a few strokes before Derek is coming, his muscles clenching around Stiles and McStiles.

The sensation overtakes them both, and both younger and older Stiles climax at the same time. Stiles thinks that shouldn’t be possible, but he chalks it up to the fact that they are both the same person, so maybe that’s why. McStiles pulls out after he gets his breath back and leaves, presumably to get something to clean themselves off.

When they are both alone, Derek slowly lifts his hips to let Stiles pull out, and then blankets himself back over Stiles. Stiles rubs his cheek against Derek’s head where it’s resting against his chest.

“That was awesome,” Stiles says. 

“Next time, we’re not having an audience.”

Stiles’s heart stutters. “Next time?”

Derek lifts his head to rest his chin on Stiles’s chest. “ _Next_ time, we’re going to be alone and I’m taking my time.”

Stiles beams. “I’m looking forward to it.” 

The door creaks when Older Stiles returns with a few wet washcloths. He hands one to both of them then ventures over to his pile of clothes to start putting them back on.

“Going already? We don’t get some after-sex cuddles?” Stiles asks, sitting up after Derek moves off of him.

“I think Derek can handle that,” McStiles says with a wink. “But yeah, I can actually hear Deaton right now, which, weird, so it’s time for me to go.”

“Oh, okay. Well uh… thanks?”

McStiles, now fully clothed with his hands in his pockets, laughs. “You’re welcome. Although, I was really being selfish and self-serving.” He looks towards Derek, who’s back in his boxers, apparently waiting for McStiles to leave so he _can_ cuddle Stiles. “I know you feel you have to protect everyone, but you’re not alone, okay? You have me. Well… him,” he waves a hand at his younger self sitting next to Derek. “You’ll always have us.”

Stiles reaches over to take Derek’s hand in his and nods in thanks at his older self. Derek intertwines their fingers together and gives Stiles a small smile. 

“Welp folks, Deaton’s getting louder and telling me what to do, so I’m off. Tell Scott to chill out and play more video games with you, and Derek, remind Isaac that you care about him cause he forgets sometimes. Oh, and… since I’m here… what’s the crisis at the moment?” 

“We’ve got a fairy problem,” Derek answers to which Stiles sits stunned because he hadn’t heard about that, must have been why Derek was crawling into his window.

“Ahhh, yes. Deaton has a book on them, so ask him about it, and when you do approach them, send Scott and Isaac. They like them better. Trust me, it’ll be fine.” He turns and yells, “Yes I can hear you! Stop yelling, Derek, I am coming.” He turns back to Stiles and Derek for one last good bye. “My Derek is going to be so jealous of himself. I can’t wait to tell him,” he says and then disappears. 

Stiles and Derek sit in silence for a few minutes staring at the spot where McStiles had been standing. “That was weird.”

“Understatement,” Derek grumbles. He picks up Stiles’s boxers from the floor and throws him at his face.

He puts them on and gathers up the washcloths and throws them in his hamper. He sits back down on the bed and looks up at Derek who is shifting his feet. “Is my Derek going to stay?” he asks, smoothing the blankets next to him. 

Derek rolls his eyes and takes Stiles’s invitation to sit next to him. “Only if you don’t refer to me in 3rd person.”

“Ugh, fine.” Stiles lays down and shuffles under the covers and moves over for Derek to slide in next to him. Derek drapes his arm over Stiles’s waist and pulls him back to his chest. “Night, Derek.”

Derek kisses the back of his neck and squeezes him tighter. “Good night, my Stiles.”

**Author's Note:**

> Oh gosh, Grimm. So, I've never written a threesome, OR Sterek sex, so like I'm sorry. It's the thought that counts right??? Bottom!Derek with some DP makes up for it, yeah??? Happy birthday my dear!! Thanks for being so awesome and wonderful! *HUGS*
> 
> For anyone else that's interested, I have one of those [tumblr things](http://literaryoblivion.tumblr.com)


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